This invention relates in general to product packaging and more specifically to a method and device for packaging chemicals.
When chemicals are transported in route to their final destination they need to be placed in a container that will ensure that the chemicals will not leak into the surrounding environment. When chemicals spill out of their container, they can create a variety of health, safety, and environmental problems. Thus it is imperative to safeguard against chemicals from leaking into the surrounding environment. Therefore, before chemicals are shipped, the container in which the chemicals are placed must be able to pass the required safety tests to ensure that the chemicals will not be released from the container, even when the container has been damaged. One of the tests that is imposed by the Federal Department of Transportation on containers used in shipping chemicals is referred to as the xe2x80x98drop test,xe2x80x99 which is illustrated in FIG. 1. In order to pass the drop test, the container must not leak after it is dropped from a height proportional to the chemical""s specific gravity onto a non-yielding surface. In particular, for steel pails, the drop test must be passed for two different orientations of the container. In a first orientation the center of gravity is aligned with the point of impact and the bottom chime of the steel pail. In a second orientation as shown in FIG. 1, the pail is inverted so that the assembly is dropped on the lid. Then, the center of gravity is aligned with the point of impact and the top chime of the steel pail. The dropped samples are then observed for any leakage of the dangerous chemicals.
Designing a steel pail such that it is able to pass the drop test and contain the chemicals without leaking is a challenging task. The difficulty of this task is amplified when it is desired to design a steel pail that will separately house two chemicals. The general design for such a container, commonly referred to as a pail and cradle, encompasses a plastic cradle, which rests along the upper lip of the pail and separates the chemicals. The prior art cradle and pail designs have failed to pass the drop test consistently. The traditional cradle and pail designs often failed the drop test because the cradle slid off the top lip of the pail and down into the dangerous chemical. Traditional cradle and pail designs also frequently failed when the seal along the top of the pail was broken, thus allowing the dangerous chemicals to leak out of the container.
The present invention provides in one aspect a container system for storing and transporting one or more chemicals, comprising a pail having a bottom joined with one or more sidewalls forming an opening, with the upper end of the sidewalls forming a rim. The system further comprises a cradle having an interior surface forming a storage receptacle and an opening with a circumferential rim forming a groove aligned for mating with the rim of the pail. A gasket is mounted within the cradle groove. The cradle further comprises an elongated return extending down from the rim. The lid for the pail comprises a circumferential groove with a gasket positioned therein and aligned for reception over the rim of the cradle and the pail rim, and one or more lugs for crimping the lid and cradle to the pail.
The present invention provides in another aspect a method of collectively packaging two chemicals separately, comprising the steps of placing a first chemical into the bottom portion of a pail; inserting a gasket under a rim formed at the top of a cradle; inserting the rim of the cradle onto the rim of the pail, wherein the cradle has an extended return that outwardly extends from the cradle rim; placing a second chemical in a recess of the cradle; mounting a groove of a lid having a gasket mounted therein over the rim of a cradle; and crimping one or more lugs of the lid so that the crimped lugs secure the extended return of the cradle to the sidewall of the pail and seal the lid to the pail.
The present invention provides in yet another aspect a cradle for use in a pail comprising an inner surface forming a recess and an opening having a circumferential rim for receiving a lip of a pail; and an extended return outwardly extending down from the rim.
The present invention provides in still another aspect a container system for storing and transporting one or more chemicals, comprising a pail having a bottom joined with one or more sidewalls forming an opening bounded by a circumferential rim. The container system further comprises a cradle having an opening defined by a circumferential rim forming a groove aligned for mating with the rim of the pail. A lid for the pail comprises a circumferential groove aligned for reception onto the rim of the cradle and the rim of the pail, and one or more lugs for securing the lid and the cradle to the pail. The cradle further comprises a return extending outwardly from the cradle rim, with the return having a length sufficient to be clamped by the lugs against the sidewall when the lid lugs are crimped onto the assembly.